Bis-(polyhalovinyl or polyhaloethyl) trisulfides

ABSTRACT

BIS-(TETRAHALOETHYL) TRISULFIDES AND BIS-(TRIHALOVINYL) TRISULFIDES. THESE TRISULFIDES ARE PREPARED BY REACTING TETRAHALOETHYLSULFENYL CHLORIDE OR TRIHALOVINYLSULFENYL CHLORIDE, RESPECTIVELY, WITH HYDROGEN SULFIDE. THE TETRAHALOETHYL COMPOUNDS ARE USEFUL AS SEED DISINFECTANTS; WHEREAS THE TRIHALOVINYL MATERIALS ARE ALGICIDAL.

United States Patent C 3,574,767 BIS-(POLYHALOVINYL R POLYHALOETHYL) TRISULFIDES Gustave K. Kohn, Berkeley, Calif., assignor to Chevron Research Company, San Francisco, Calif.

No Drawing. Filed Nov. 29, 1968, Ser. No. 780,292 Int. Cl. C07c 149/12; A01n 21/00, 9/12 U.S. Cl. 260-608 Claims ABSTRACT OF THE DISCLOSURE Bis-(tetrahaloethyl) trisulfides and bis-(trihalovinyl) trisulfides. These trisulfides are prepared by reacting tetrahaloethylsulfenyl chloride or trihalovinylsulfenyl chloride, respectively, with hydrogen sulfide. The tetrahaloethyl compounds are useful as seed disinfectants; whereas the trihalovinyl materials are algicidal.

FIELD OF INVENTION This invention relates to bis-(polyhalohydrocarbyl) trisulfides and their use as seed disinfectants,

INVENTION DESCRIPTION The trisulfides of this invention are bis-(trihalovinyl) and bis-(tetrahaloethyl) trisulfides. Accordingly, the polyhalohydrocarbyl group of these compounds may be de scribed as being free of acetylenic unsaturation and consisting of 2 carbon atoms and, when the group is olefinically unsaturated 3 halogen atoms of atomic number 17 to 35 or when the group is saturated 4 halogen atoms of atomic number 17 to 35 and one hydrogen atom. Halogens of atomic number 17 to 35 are Cl and Br. The bis-(tetrachloroethyl) trisulfides are preferred because of their superior seed disinfectant properties.

The preferred bis-(tetrachloroethyl) trisulfides may be represented by the formula wherein 4 of the Xs on each ethyl group represent chlorine and the remaining X represents hydrogen. Included in this genus are bis-(l,l,2,2-tetrachloroethyl) trisulfide and bis-(1,2,2,2-tetrachloroethyl) trisulfide.

Other trisulfides of this invention are exemplified by bis- (tetrabromoethyl) trisulfide, bis- (tribromovinyl) trisulfide, bis-(1,2-dibromo-2,2-dichloroethyl trisulfide and bis-(2- chloro-l,2-dibromovinyl) trisulfide.

These trisulfides may be prepared by reacting polyhalohydrocarbyl sulfenyl chlorides with hydrogen sulfide. This reaction, as applied to the preferred trisulfides of this invention, proceeds according to the following equation:

where X is as defined previously.

The sulfenyl chloride is added slowly to hydrogen sulfide dissolved in a non-polar solvent. Reaction temperatures of about C. to +50 C. will normally be used. Preferably the temperature will be maintained between 0 and 5 C. to keep the reaction rate controlled. In this respect, the reaction is exothermic and care should be taken when higher temperatures are used. The reaction time will depend principally on the temperature. Usually it will be completed Within 2 to 24 hours. However, the reaction between hydrogen sulfide and trichlorovinylsulfenyl chloride is instantaneous.

As usually practiced, the reaction is carried out at atmospheric or autogenous pressure. Some positive pressure may be applied if ararngements are made to vent the hydrogen chloride formed.

The non-polar solvents for this reaction are neutral organic liquids, examples being diethyl ether, dichloromethane, tetrahydrofuran, and acetonitrile. It is preferred that the solvents be low boiling in order to facilitate their separation and recovery of the trisulfide product.

Generally, an excess of H S is used in the reaction. However, this excess does not hinder the reaction or prevent the formation of large quantities of the desired product. In general, the yield is in the range of 65-85% of theoretical based on the sulfenyl chloride. Stoichiometric amounts of H 8 and sulfenyl chloride may be used if desired.

EXAMPLES The preparation of the trisulfides of this invention is exemplified by the following examples. Percentages are by weight,

Example 1 A 2-liter flask equipped with a gas inlet tube, a gas outlet tube, a thermometer, and a magnetic stirrer was immersed in an ice bath. The gas outlet tube was connected to a glass U-tube partially filled with mineral oil to exert a slight back pressure. This flask was charged with 1 liter of ether which was allowed to cool to about 0-5 C. Then H S was passed into the cold ether until the ether was saturated; about 25-30 grams (about 0.85 mol) of H S was dissolved. A cold solution of 93.7 grams (0.4 mol) of 1,1,2,2-tetrachloroethylsulfenyl chloride in ml. of ether was added dropwise to the stirred H S solution over a period of about 15 minutes. Then the mixture was gradually warmed to 20 C. and allowed to stand at this temperature for 64 hours. At the end of this time, nitrogen was passed through the solution for 20 minutes to strip out all unreacted H 8 and to concen-' trate the solution by removing most of the ether. The resulting solution was filtered, and the remaining ether was removed by heating at 90 C. under less than 1 mm. of pressure. The material was filtered again through a Celite filter aid to give 77 grams of crude bis(1,1,2,2-tetrachloroethyl) trisulfide.

Analysis.Calculated for C H Cl S (percent): C1, 66.0; S, 22.4. Found (percent): C1, 6495; S, 23.71. An infrared spectrum had strong adsorption peaks at 8.0, 8.25, 9.8, 12.4, 13.2 and 13.95 microns. The 19.0-micron adsorption band typical of SCl bonding was absent.

Example 2 Essentially the same procedure as Example 1 was followed using 32.3 grams (0.163 mol) of trichlorovinylsulfenyl chloride and 7.5 grams (0.22 mol) of H 5. The crude product was passed onto a column of 180 grams of silica gel. It was eluted with hexane, thereby giving 27 grams of a clear yellow liquid.

Analysis.-Calculated for C Cl S (percent): Cl, 59.7; S, 26.95. Found (percent): CI, 59.6; S, 26.65. An infrared spectrum showed strong adsorption at 6.5 and 11.3 microns.

Example 3 Essentially the same procedure as Example 2 was followed using 23.4 grams (10.1 mol) of 1,2,2,2-tetrachloroethylsulfenyl chloride and 10 grams (0.3 mol) of H S. The product was a brown liquid weighing 19.3 grams.

, Analysis.-Calculated for C H Cl S (percent): Cl, 65.8; S, 22.38. Found (percent): Cl, 62.8; S, 22.57. An infrared spectrum showed strong adsorption at 12.35 and 13.3 microns.

3 UTILITY The saturated trisulfides of this invention are useful for controlling pathogens such as fungi, bacteria and yeasts which attack seeds and other vegetative hosts. They are particularly useful for disinfecting crop and feed seeds such as corn, oats, barley, wheat, peas, beans, cotton and sugar beet. Typical organisms controlled by these trisulfides are Fusarium, Penicillium, Aspergillus, Rhizopus, Rhizoctonia and yeast.

One or more of the saturated trisulfides of this invention will be applied to the seed or other host in amounts which are toxic to the pathogens. About 0.2 to oz. trisulfide per 100 lbs. seed will usually be needed to give adequate control. The trisulfide may be applied in liquid or solid form. When used in solid form the trisulfide will be absorbed on a particulate carrier such as talc, clay, silica, charcoal, limestone, loam and the like, These solid formulations may be dusted onto the seed by established techniques. Alternatively, they may be applied as an aqueous slurry by spraying or dipping. When applied as a liquid, the trisulfide will be dissolved in solvents such as benzene, toluene and lower alkylketones, e.g., acetone and methyl isobutyl ketone. These solutions may be applied as the above-mentioned aqueous slurry with the addition of an emulsifier.

In addition to the solid or liquid diluent formulations of these trisulfides, they may also contain dispersing agents, adjuvants, plant nutrients, binders and other pesticides.

The use of the saturated trisulfides of this invention as seed disinfectants was illustrated by the following tests.

Bis-(l,1,2,2-tetrachloroethy1) trisulfide was dissolved in a small amount of acetone. A small portion of emulsifier (alkylarylpolyoxyethylene glycol and fatty acid) was added and the solution was diluted with water to the desired concentration. This mixture was distributed on the wall of a glass jar. Corn seed, which has been inoculated previously with a spectrum of fungi and yeast and kept at 4 C. to prevent organism growth, were rolled in the jars until they were coated and the mixture was completely absorbed on them. Following this treatment the seeds were placed on potato dextrose agar plates and incubated. After 2 days the organism growth was measured and the percent organism control calculated. For comparison a known structurally related seed disinfectant, bis-(trichloromethyl) trisulfide, was tested by the above method in side-by-side tests. The results of these tests are tabulated below.

The above data evidence the substantial superiority of the tetrachloroethyl compounds over the most closely related known compound.

Bis-(1,1,2,2 tetrachloroethyl) trisulfide has also exhibited bactericidal activity against Erwinia and Pseudomonas at 500 p.p.m.

Unsaturated trisulfides of this invention are useful for controlling algae and related aquatic plants. They may be used to control such organisms in aqueous industrial efiluents and cooling streams, lakes, streams, canals and pools. When so used an algicidal amount of one or more of these trisulfides is added to the aqueous growth environment of the organism. This amount will normally range between about 0.1 and p.p.m.; more usually between 0.1 and 10 p.p.m. In terms of lbs. of trisulfide per acre of water one foot deep, 0.1 to 10 p.p.m. is equal to about 0.3 to 18 lbs, per acre water one foot deep. These trisulfides may be applied to the organisms environment as water-dispersible powders or in solution with watermiscible solvents.

Bis-(trichlorovinyl) trisulfide was tested by the following method to illustrate the above-described algicidal utility of the unsaturated trisulfides of this invention.

An acetone solution of equal parts of trisulfide and a surfactant was prepared. This solution was mixed with a nutrient broth in a quantity sufiicient to give a concentration of 2 p.p.m. trisulfide. Four replicate 150 ml. specimen cups were filled with this mixture. 350400 mg. of Euglena was added to each specimen cup and the cups were then placed in an environment chamber for incubation. The cups were observed periodically for algae growth. The algicidal effectiveness of the trisulfide was determined based on a final observation of algae growth after 10 days.

Bis-(trichlorovinyl) trisulfide provided control of Euglena in the above test.

I claim:

'1. Bis-(polyhalohydrocarbyl) trisulfide wherein the polyhalohydrocarbyl group is free of acetylenic unsaturation and consists of 2 carbon atoms and when said group is olefinically unsaturated 3 halogen atoms of atomic number 17 to 35 or when said group is saturated 4 halogen atoms of atomic number 17 to 35 and one hydrogen atom.

2. The trisulfide of claim 1 wherein said halogen atoms are chlorine.

3. Bis-(tetrachloroethyl) trisulfide.

4. The trisulfide of claim 3 wherein the tetrachloroethyl group is 1,1,2,2-tetrachloroethyl.

5. The trisulfide of claim 3 wherein the tetrachloroethyl group is 1,2,2,2-tetrachloroethyl.

Organism, percent control Concen- Sum tration, Fusnrium Penicillium and Rhizopus of all Tflslllfide oz./cwt. spp. Aspergillus spp. spp. fungi yeast Bis-(1,1,2,2-tetrachloroethyl) trisulfide 0 i Comparison compound Bls-(trichloromethyl) trisulfide g References Cited FOREIGN PATENTS 949,374 1964 Great Britain 260-608 970,784 1964 Great Britain 260-608 CHARLES B. PARKER, Primary Examiner D. R, PHILLIPS, Assistant Examiner U.S. Cl. X.R. 

